The present invention relates in general to accessing an automotive vehicle or vehicle functions using spoken voice commands outside the vehicle, and, more specifically, to an access system that uses a vehicle window as part of a microphone-like structure for detecting spoken voice commands.
Passive keyless entry is a technology wherein the user of a vehicle is able to unlock the vehicle doors without manually inserting a key in a lock. Instead, the user carries a wireless transponder or transceiver (i.e., a fob) which carries security data that is automatically exchanged with the vehicle in order to authenticate the user. Touching a door handle is often used to initiate interrogation of the fob within a small region surrounding the door.
Some vehicle doors, such as a rear liftgate on a sport utility vehicle or a sliding side door on a minivan, may include powered actuators for opening the door. Activation of the powered doors can typically be done remotely by pressing a corresponding button on the fob. In order to enable a more passive method of opening the powered door (such as when the user's hands are full and it is inconvenient to press a fob button), vehicles have been introduced wherein door activation can be done by waving a foot underneath the door to trigger an ultrasonic sensor or laser sensor arranged to detect motion in a target area beneath the door. However, some problems have been encountered with these activation systems when the user's foot does not achieve the correct placement beneath the sensor, or when the sensor becomes dirty from road debris or mud or snow. Unintended opening is also possible if the user inadvertently causes motion in the target area for a purpose unrelated to opening the door. Some users may also find it difficult to hold large loads in their hands while having to stand on one foot to activate the sensor. Additionally, the motion/proximity sensors tend to be relatively expensive.